In the case where refrigerant is supplied to a heat exchanger with a plurality of heat transfer paths, such as an evaporator for a refrigeration unit, it is necessary to control the refrigerant supplied to the respective heat transfer paths with one expansion valve such that refrigerant coming out from the expansion valve is equally divided into the respective heat transfer paths by a refrigerant flow divider.
In the case of a refrigeration unit shown in FIG. 1, for example, refrigerant compressed by a compressor 1 is condensed in a condenser 2, and after that, sent to an expansion valve 3. The refrigerant of gas-liquid two-phase flow discharged from the expansion valve 3 is equally divided into the respective heat transfer paths of an evaporator 5 by a refrigerant flow divider 4 so as to be evaporated in the evaporator 5, and after that, is merged in a header 6 and recirculated to the compressor 1.
The refrigerant flow divider used in the above described refrigeration unit functions to equally divide the refrigerant, and the higher the degree of equality in the division is, the better.
Some conventional refrigerant flow dividers are made up of an inlet pipe, a main body of the refrigerant flow divider of which the inside is a cavity, and a plurality of branching pipes through which refrigerant flows out (see Patent Document 1). In other conventional refrigerant flow dividers, an orifice or a nozzle is provided inside the flow divider or an inlet pipe such that the flow rate of two-phase refrigerant increases, and thus, nonuniform flow is reduced (see Patent Document 2).
[Patent Document 1] Japanese Laid-Open Utility Model Publication No. 60-2775
[Patent Document 2] Japanese Laid-Open Patent Publication No. 2002-188869